Our Planet draws a straight line between climate change, sea-ice loss, bigger haul-outs, overcrowding, climbing walruses, and falling walruses. “It is not a normal event,” says Lanfear. “It’s such a tangible, obvious thing to show people. It’s clear as day.”
But a few walrus scientists who saw the clip have questioned parts of this narrative—including the claim that walruses are climbing “to find space away from the crowds.” “Walruses thrive on crowds and haul out in tight groups, even when space is available,” says Lori Quakenbush from the Alaska Department of Fish and Game. Also, in the sequence, it looks as if the beach beneath the teetering walruses is relatively empty. What crowds are they escaping from?
This confusion arises from the ways in which documentaries elide space and time. Lanfear clarifies that the sequence includes footage from two separate beaches—one with the 100,000-strong congregation and one with the falls. At the latter, walruses started climbing only once the area beneath the cliffs had completely filled up; gregarious or not, they had no room. Once at the top, they rested for a few days, and walked off only after the beaches below had emptied. Indeed, as the narration suggests, the sounds of their departing comrades may have lured the cliff-top walruses off the edge. “They seemed to all want to return to the sea to feed as a group,” Lanfear says.
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Quakenbush and others also doubt that the climbs and falls are related to climate change, because such tragedies have been reported since before sea ice showed substantial declines. “Walruses have shown similar behavior on the U.S. coastline when space and ice were not an issue, and the reason is unknown,” says Lori Polasek from the University of Alaska Fairbanks. For example, in three successive years, from 1994 to 1996, dozens of male walruses fell to their death from cliffs in southwestern Alaska. But Kochnev and Lanfear argue that the incident captured in Our Planet is exceptional in both the height of the cliffs and the number of walruses that plummeted and died—hundreds as opposed to dozens.
The reason for the falls might be complicated, but it’s clear that climate change is affecting the walruses. “We do believe that haul-outs have increased in size due to the loss of sea ice—in part, due to females and their calves moving to land during summer,” says Nicole Misarti from the University of Alaska Fairbanks.
These changes have affected the indigenous communities that have traditionally hunted, protected, and lived alongside walruses. The 200 Chukchi people who live in the Russian village of Vankarem are familiar with local haul-outs. But according to one resident, Vladilen Ivanovich Kavry, the gatherings have become more crowded, and the walruses look weaker. They’re edging closer to the village, and those killed during stampedes attract polar bears, which are also coming ashore because of the vanishing sea ice.